1. Field of the Invention
This invention relates generally to hand tools and more particularly to measuring and layout tools.
2. Description of the Prior Art
The prior art discloses a number of measurement tools designed for specific applications. For example, in U.S. Pat. No. 1,125,010 Doner teaches a rafter tool including a main body portion and a leg portion angling away from the main body portion. The main body portion is slotted to provide for quick, standard measurements. Similar rafter tools are disclosed in U.S. Pat. Nos. 2,965,969 of Haley, 3,010,209 of McKinley, and 2,204,927 of Cramer.
Framing squares are also described in a number of patents. For example, in U.S. Pat. No. 223,709 of Cornell a framing square including a ruler portion and an arm portion extending perpendicularly from an end of the ruler portion is taught. The ruler portion is provided with a number of slots. A similar tool is disclosed in U.S. Pat. No. 2,575,595 of Rienecker.
In German Pat. No. 2,906,921 of Wolff a layout tool is disclosed including a triangularly shaped member provided with a pair of slots, and an endpiece attached to one edge of the triangularly shaped member for engaging an edge of a work piece. The endpiece extends both above and below the surface of the triangularly shaped member such that the tool has a T shaped cross section. The tool is primarily used for marking lines along a plank in preparation for a rip cut.
What the prior art does not disclose is a construction layout tool of more general capabilities. That is to say, the prior art does not teach a tool which is adapted for measuring rafters, wall partitions, and which can also be used as a square. Thus, a construction worker must own and carry a number of separate tools for those tasks.